Originally Posted by thestr0ng1
From that perspective... I am a middle school math teacher (grades 6-8) and it is not easy or practical to differentiate instruction when some kids are at grade level, some barely remember basic math -- think adding and subtracting single digit numbers -- and when you turn your attention to one student or group, many others in class will get off task.

I agree with what you've written here. IMO, two ways to help solve this problem are to:

1) group children by ability/skill level, starting in kindergarten or first grade;

2) not move them to the next subject until they're proficient at the second one.

Unfortunately, many schools have policies against these approaches, which creates these problems.